Thermal gas-valve.



W. C. NORTON.

THERMAL GAS VALVE.

APPLICATION FILED MAR. 26. I9I4.

l 'l Patented May 21,1918.

Wfneses:

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THERMAL GAS-VALVE.

Specification of Letters Patent.

Patented May 21, 1918.

Application led March 26, 1914. Serial No. 827,461.

To all whom t may concern:

Be it known that l, WILLIAM C. NORTON, a citizen of the United States, residing at Salem, in the county of Essex and State of Massachusetts, have invented an Improvement in Thermal Gas-Valves, of which the following is a specification.

This invention is intended as an improvement upon the thermal gas valve, shown and described in my Letters Patent #717,904, dated January 6, 1903, and the essential object is the construction of the valve to the end that the fusible ele-ment is mounted in a detachable gas-tight holder and is exposed to the air, whereby the said fusible element can be easily replaced and is much more sensitive than when inclosed as in my former patent. Further objects of my invention are, to make the connections between the valve-cap and holder, and the fusible element and valve-stem, additionally gas-tight, by causing the upper end portion of the supplemental valve-plug to fit tightly against the inner end portion of the valvecap; to provide a novel and more efficient connection between the fusible element and its holder or support; to provide an intimate and gas-tight engagement between the supplemental valve-stem and the fusible element.

A valve embodying my invention comprises a valve casing and its ports, a hollow rotatable main valve-plug seated within said casing and having corresponding ports, a supplemental valve-plug arranged within said hollow main valve-plug, an actuating spring for said supplemental valve-plug, a 4

cap for said main valve-plug, a holder for a fusible element centrally attached to said cap and having a center-hole, an exterior fusible element connected with said holder and having a center-hole, and a stem connected to said supplemental valve-plug and in intimate engagement with said fusible element, arranged to hold said supplemental valve-plug in elevated position with its actuating-spring under compression.

Figure 1 is a side elevation of a thermal gas-valve embodying my invention.

Fig. 2 is a longitudinal section of the same showing the parts in their normal position.

Fig. 3 is a similar section showing the parts after the fusible element has been fused.

The casing 4 has a rotatable main valveplug 5 suitably tapered and fitted thereto and also the usual ports which coperate with ports in the main valve-plug 5. The main valve-plug 5 is made hollow and extends beyond the casing 4 to provide within it a chamber 20 to receive the supplemental valve-plug 6, when the latter is in elevated position and to assist in guiding said supplemental valve-plug in its downward movement into valve-closing or seating position, the diameter of the upper portion of the chamber being slightly greater than the diameter of thel upper end portion of the plug 6. The lower interior portion of the valve-plug 5 is of frusto-conical shape to form a seat for said similarly shaped supplemental valve-plug 6.l

The upper' end-portion of the chamber of the main valve-plug 5, is closed by a cap 7 screwed therein, having its outer portion in the form of a nut to admit of said cap together with the main valve-plug 5 attached thereto, to be manually operated by a wrench. As a precaution against the unscrewing of the cap by turning the main valve-plug, the latter is additionally secured to the said cap 7, by the set-screw 8. Through the cap 7 is a center-hole 9, having an annular shoulder 10, intermediate its length. The upper end-portion of said center-hole 9, extending preferably from said shoulder 10 outward, is screw-threaded to receive the holder for the fusible element.

The holder for the fusible element consists of a screw-nipple 11, having a centerhole 12, through it, the upper end-portion of which, adjacent said center-hole, is countersunk, thereby forming a beveled seat 13, and a fusible metal disk 14, is arranged at the outer end of said nipple and is extended over said center-hole and its edge brought into engagement with said seat 13.

Rigidly and centrally attached to the lower end-portion of the supplemental valve-plug 6 is a rod or stem 17 which extends outward through the aforesaid main valve-plug cap 7, and nipple, and has a screw-threaded portion at its outer end, which intimately engages the screw-threaded center-hole in the fusible metal disk 14. A stem-holding and straindistributing member 16, here shown as a nut, is arranged upon the upper projecting screw-threaded portion of said rod or stem 17, said nut 16 bearing uponfthe top of the fusible disk 14 and being of an area approximately equalmg the area of the center-hole 12, through the nipple. It may be here observed that the connection between the rod or stem 17, and the fusible disk 14, is gas-tight.

F or the purpose of causing or positively moving the supplemental plug rod, or stein, 17, to close the valve upon the fusing of the fusible disk 14, the spiral spring 18, is arranged in the recess 19, of the supplemental valve-plug 6, and in the center-hole 9 in the cap 7. The lower end of said spiral spring 18 engages the bottom of said recess 19, in the said supplemental valve-,plug 6, and the upper end of said spring` engages the shoulder 10. This spring is held under tension in readiness to act by the nut or strain-distributing membery 16, which engages the fusible element 14 and holds the supplemental plug 6, in elevated position.

The conformation of the fusible metal disk 14, to the countersunk circular opening adjacent the center-hole12,of the holder 11, produces on said disk a'k Beveled edge, or reduced edge-portion, which forms the supporting portion of the fusible metal disk. Substantially the entire area of saidv reduced edge-portion of said fusible disk is in engagement with the screw-nipple 11, and is thickest Where the greatest stress is carried by said disk, namely along the interior circumference of the holder, and is thinnest along the exterior circumferential edge of said disk, Where the supporting stress is least. By means of such a beveled supporting edge, the said fusible disk is strong enough to stand the strain caused by the tensioned spring 18, while at the same time the exterior edge portion of the said supporting portion of said disk, is made thin, which tends to make the said fusible disk 14, more sensitive to a rise in temperature and to hasten the separation of the disk from its holder when fusion begins.

I claim A thermal gas valve including a casing having ports, a rotatable main valve having corresponding ports and extended beyond the casing, an end cap closing the `end of the main valve, and projecting beyond the innersurface of such main valvev to form` a shoulder, means for'securing. the cap in adt the normal position of the supplementalv valve bearing against the shoulder of the end cap.

In testimony whereof, I have signedy my name to this specification, in the presence of two subscribing Witnesses.

WILLIAM C. NORTON.

Witnesses:

B. J. Norms, I-I. B. DAvrs.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. C. 

